Thermodynamics of Arsenates, Selenites, and Sulfates in the Oxidation Zone of Sulfide Ores. XV. Synthetic Analog of Alfredopetrovite: Composition, Properties, and Stability Limits

• Published in: Geology of ore deposits Vol. 65; no. 7; pp. 645 - 655
• Main Authors: Ushakova, K. L., Charykova, M. V., Krivovichev, V. G., Efimenko, N. M., Platonova, N. V., Bocharov, V. N., Mazur, A. S.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.12.2023; Springer Nature B.V
• Subjects: Aluminium; Aluminum; Aluminum chloride; Analytical methods; Arsenates; Earth and Environmental Science; Earth Sciences; Infrared spectroscopy; Magnetic resonance spectroscopy; Mathematical analysis; Mineral Resources; NMR; NMR spectroscopy; Nuclear magnetic resonance; Ores; Oxidation; Raman spectroscopy; Room temperature; Saturation; Selenite; Selenites; Selenium; Solubility; Spectroscopy; Stability analysis; Sulphides; Surface stability; Synthesis; Thermal analysis; alfredopetrovite; aluminum; selenite minerals; selenium
• ISSN: 1075-7015; 1555-6476
• DOI: 10.1134/S1075701523070139

The purpose of this work was to synthesize hexahydrate aluminum selenite Al 2 (SeO 3 ) 3 ⋅6H 2 O (analogous to the mineral alfredopetrovite) and study its solubility in water. Al 2 (SeO 3 ) 3 ⋅6H 2 O is synthesized from AlCl 3 and Na 2 SeO 3 solutions at room temperature and atmospheric pressure. The obtained samples were studied using powder diffractometry, infrared and Raman spectroscopy, energy-dispersive X-ray microanalysis, nuclear magnetic resonance spectroscopy, and complex thermal analysis. Solubility was determined by isothermal saturation in ampoules at 25°C. Solubility products were calculated using Geochemist’s Workbench software package (GMB 9.0, SpecE8 program). As a result of the calculation, the average value logKsp[Al 2 (SeO 3 ) 3 ⋅6H 2 O] = –28.3 ± 0.5 was obtained. An Eh–pH diagram is constructed for the Al–Se–H 2 O system, which was used to analyze the stability of alfredopetrovite in near-surface conditions.